Malware writers are using a luxury name to hack into your computer. Security watchdog Sophos is reporting that e-mails coming from a Tiffany.com address and carrying the attachment copy.zip are looking to install a malicious Trojan horse on your PC.

"This may be a deliberate ploy on the part of the criminals behind the attack to tempt more people into opening the attachment," Graham Cluley, senior security analyst at Sophos, wrote in a blog post. "Of course, it's child's play to forge e-mail header information, and there is no suggestion that the messages were really sent by Tiffany's," the high-end jeweler known for its little blue gift boxes tied smartly with white ribbon.

"If anything," Cluley said, the folks at Tiffany's "are also victims of this campaign."

Check Your Zipper

We asked Richard Westmoreland, a security analyst at security-as-a-service provider SilverSky, to chime in on the latest Trojan to make headlines. He explained that most successful e-mail Trojans now hide their malicious payload within zip files and depend on social engineering to get the end user to execute it.

"Companies can't block zip file attachments because it would impact legitimate business, however, e-mail filtering with virus scanning should still be able to inspect the contents of unencrypted zip files," Westmoreland said.

"It is important to scan for viruses both at the e-mail gateway and on the users' workstations, but equally important to remind employees not to open files they were not already expecting. In situations where antivirus does not yet have signatures for the payload and an employee still mistakenly opens the file, the workstation will likely start exhibiting suspicious behavior and the compromise could be detected by a SOC that is that network."

Copy Cat Social Engineers

Westmoreland's colleague Evan Keiser, also a security analyst with SilverSky, told us the Tiffany & Co. Trojan is just another copy of Bredolab (recognized by Sophos security scans as Mal/BredoZp-B). It leverages a foothold the bad guys have within Tiffany's mail server for a decent infection campaign.

"I believe it was pretty smart to utilize Tiffany's, as most people actually waiting on jewelry from them probably have some seriously high-limit credit cards," he said. "Tiffany's mail server was used to send out spam with Bredolab attached."

We also caught up with Grace Zeng, a research analyst at SilverSky, to get her take on the new Trojan. She told us this is not a new trick. Security experts have already seen a large number of fake invoice or delivery notice e-mails from , FedEx and Amazon that contain malware or to exploit kits. In her opinion, this Tiffany email is not disguised well. "Who would expect an export license from Tiffany & Company," she asked, "when an order invoice would be more enticing?"

"On a related note, Symantec last week alerted that several social-engineering attacks were reported in Europe. Those attacks specifically targeted the finance department of some organizations," Zeng said. "The victim received a phone call from a person who claimed to be an employee of the organization and the victim was asked to process an invoice that he/she was about to receive. People are very easy to fall victim to such sophisticated attack as opposed to just an email or a phone call."

Watch Your In-Box

The specific email shown as an example in Graham Cluley's blogpost has a subject line that says, "invoice copy" -- and it's supposedly from Karen Parker at Tiffany.com. The body of the email reads:

Kindly open to see export License and payment invoice attached, meanwhile we sent the balance payment yesterday.
Please confirm if it has settled in your account or you can call if there is any problem.

Thanks
Karen parker

"Whatever you do, don't open the file attached to the email," Cluley warns. Contained inside the file invoice 'copy.zip' is the malicious Trojan horse, designed to compromise your computer.

Warn your friends and users, and as a general rule, remember to never open any attachment from an unknown source or even from a known source if you weren't expecting it or it just doesn't look quite right.